svn commit: r356082 - stable/12/contrib/elftoolchain/elfcopy

[Aleksandr Rybalko]

Author: ray
Date: Wed Dec 25 22:07:24 2019
New Revision: 356082
URL: https://svnweb.freebsd.org/changeset/base/356082

Log:
  MFC r352875:
  
  Put sections into expected offset in binary format.
  Calculate binary file offset using address field, bacause software know only offset to known data, not where to load segment.
  With that patch, kernel .data section can have any alignment/offset - kernel boor fine.
  
  PR:		235391
  Reviewed by:	markj
  Differential Revision:	D21827

Modified:
  stable/12/contrib/elftoolchain/elfcopy/binary.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/contrib/elftoolchain/elfcopy/binary.c
==============================================================================
--- stable/12/contrib/elftoolchain/elfcopy/binary.c	Wed Dec 25 20:57:24 2019	(r356081)
+++ stable/12/contrib/elftoolchain/elfcopy/binary.c	Wed Dec 25 22:07:24 2019	(r356082)
@@ -49,22 +49,23 @@ create_binary(int ifd, int ofd)
 	Elf *e;
 	Elf_Scn *scn;
 	Elf_Data *d;
+	Elf64_Addr baseaddr;
 	GElf_Shdr sh;
-	off_t base, off;
+	off_t baseoff, off;
 	int elferr;
 
 	if ((e = elf_begin(ifd, ELF_C_READ, NULL)) == NULL)
 		errx(EXIT_FAILURE, "elf_begin() failed: %s",
 		    elf_errmsg(-1));
 
-	base = 0;
-	if (lseek(ofd, base, SEEK_SET) < 0)
+	baseoff = 0;
+	if (lseek(ofd, baseoff, SEEK_SET) < 0)
 		err(EXIT_FAILURE, "lseek failed");
 
 	/*
 	 * Find base offset in the first iteration.
 	 */
-	base = -1;
+	baseoff = -1;
 	scn = NULL;
 	while ((scn = elf_nextscn(e, scn)) != NULL) {
 		if (gelf_getshdr(scn, &sh) == NULL) {
@@ -76,14 +77,16 @@ create_binary(int ifd, int ofd)
 		    sh.sh_type == SHT_NOBITS ||
 		    sh.sh_size == 0)
 			continue;
-		if (base == -1 || (off_t) sh.sh_offset < base)
-			base = sh.sh_offset;
+		if (baseoff == -1 || (off_t) sh.sh_offset < baseoff) {
+			baseoff = sh.sh_offset;
+			baseaddr = sh.sh_addr;
+		}
 	}
 	elferr = elf_errno();
 	if (elferr != 0)
 		warnx("elf_nextscn failed: %s", elf_errmsg(elferr));
 
-	if (base == -1)
+	if (baseoff == -1)
 		return;
 
 	/*
@@ -110,8 +113,8 @@ create_binary(int ifd, int ofd)
 		if (d->d_buf == NULL || d->d_size == 0)
 			continue;
 
-		/* lseek to section offset relative to `base'. */
-		off = sh.sh_offset - base;
+		/* lseek to section offset relative to `baseaddr'. */
+		off = sh.sh_addr - baseaddr;
 		if (lseek(ofd, off, SEEK_SET) < 0)
 			err(EXIT_FAILURE, "lseek failed");